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Dr.M.Ben Masoud
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` Difficult airway is the single most important cause of
anesthesia related morbidity andmortality.
` 30% of deaths attributed to anesthesia are associated with
inadequate airwaymanagement.
` Unexpected difficultycatastrophies.` Airway
assessment.detecting difficult laryngoscopy and tracheal
intubation.only?` Intubation is difficult in 1:50 case, impossible
in 1:2000.` Face mask ventilation is difficult in1:20, impossible
in 1:1500.` Rescue techniques fail in 1:20 cases.
History:
` Congenital airway difficulties e.g. Pierre robin, downs
syndrome..` Acquired airway difficulties e. g. R.A., pregnancy,
O.A, D.M, etc` Reported previous anesthesia problems.` Iatrogenic
problems cervical surgery, radiotherapy, fusion
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E xamination:` Adverse anatomical features.` Acquired problems.`
Mechanical limitation.` Poor dentition.` Facial hair.` Nasal
patency in nasal intubation.` E quipment .e.g. dental wiring,
fixator, collaretc.Radiology:` CT, MRI, X-ray.` Plain radiograph
are poor predictors.
` Predictive tests:` Laryngoscopy and tracheal intubation needs
clear line of view from the upper teeth to
the glottis.`
Mouth opening, extension of upper c. spine, create submandibular
space.Cormack and Lohane classification glottic view=G1 easy,G2,
G3, G4difficult
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Cooks modified classification of laryngealview:E asy= G1+ G2A,
restricted= G2B+G3A,difficult=G3B+G4.
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Interincisor gap: the distance between the incisors with the
mouth open maximally.`
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E xtension of upper cervical spine:` When limited (7cm;
55yr.Body mass index >26 kg/m2 .History of snoring.Beards.
Absence of teeth.Facial abnormality.Receding or markedly
prognathic jaw.Obstructive sleep apnoea.
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`
L=look externally.` E =E valuate the 3-3-2 rule.The distance
between the patients incisor teeth should be >/= 3 fingers
breadths (3)The distance between the hyoid bone and the chin should
be >/= 3 fingers breadths (3)The distance between the thyroid
notch and floor of the mouth should be >/= 2 fingers
breadths (2).` M= Mallampati .` O= obstruction. airway
obstruction makes laryngoscopy and ventilation difficult . E
.g.
epiglottitis, trauma, abscess...etc.` N= neck mobility. Vital
requirement, neck collar makes intubation difficult.
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Predictors of problems of back-up techniques:
LMA insertion:-, rescue plan.` Inability to open the mouth
>2.5cm (impossible if
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Problems of predictive tests:` Low specificity and positive
predictive value, large false positive, sensitivity
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Difficult intubation with easy ventilation:` A calm stepwise
approach .`
Plan A failsB success, A&B fail..C success.
Difficult intubation with difficult/impossible ventilation:`
cant intubate cant ventilate` E mergencylife threatening need
correct management.` Difficult mask ventilation.LMA rescue
airway>90% choiceexperience and
situation.` Remain CICV plan D life saving.
Failed mask ventilation: always an emergency call for help, keep
assistant available.` Due to:-` Failure to maintain upper airway
patency most common.` Laryngospasm.` Laryngeal pathology.` Lower
airway pathology
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Pediatrics:
` Laryngospasm is more common.` Hypoxia occurs rapidly.` Airway
manipulation or use of suxamethonium in
presence of hypoxia may lead to bradycardia andcardiac
arrest.
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Techniques for management of elective difficult intubation:-`
Gum elastic bougie: Single most useful piece of difficult
intubating technique.` Intubating stylet rigid ` Intubation via the
classic proseal or intubating LMA: Oxygenation and ventilation
during intubation, fibroscope increases success.` The combitube:
Airway device, two lumens, two cuffs, small size recommended.`
Retrograde intubation.
cant intubate cant ventilate:
Rescue plans LMA >90%.Cricothyroidetomy.IV cannula.Surgical
airway.
Multiple attempts increase CICV situation, failed
intubation.increase risk of aspiration.
E stablish definitive airway after rescuing
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E xtubation after difficult intubation:` When the tracheal tube
is removed, the airway may occlude, reintubation much
difficult due to:-` Airway bruising and swelling, Airway
contamination, Laryngospasm due to injury,
New impairments to airway access.
E xtubation must be planned:` Prepare and check same equipment,
Have plan and backup plan, E mergency
surgical airway may still required.
Consider:-` Delayed E xtubation, ventilation in ICU,
reassessment later, Corticosteroid therapy, An
elective tracheostomy, positioning airway exchange catheter.
Before extubation:` Clear airway, good hemostasis, consider
adjuncts, empty the stomach, ensure
reversal of neuromuscular blockade, remove surgical pack,
perform leak test placepatient in best airway maintaining position,
preoxygenate, awake patient, high flowO2, monitor closely.
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` Thank you
